What is the authorisation code?
When we ask HMRC for permission to act as your tax agent, HMRC posts a letter to your home address. Inside is an authorisation code that starts with SA followed by 8 digits (for example SA12345678).
Entering this code is what lets us submit your claim to HMRC on your behalf — so it really matters! 📬
When will it arrive?
The letter usually arrives within 7 to 10 working days of us requesting it. It comes in a plain brown or white HMRC envelope, so please open your post carefully — it does not say TaxPro on it.
The code expires after 30 days
HMRC codes are only valid for 30 days from the date on the letter. If it expires, we have to request a new one and wait for the post again, which delays your refund. Enter it as soon as it arrives.
Where do I enter it?
Log in to your TaxPro account.
Open your claim — you will see a box asking for your authorisation code.
Type the code exactly as printed (SA followed by 8 digits) and press Submit.
We then confirm it with HMRC, usually within a few hours. ✅
Common mix-up: this is not your UTR
Your UTR is a 10-digit number on a different HMRC letter. The authorisation code always starts with SA. If your code will not submit, check you are not entering your UTR by mistake.
Lost it or never arrived?
If it has been more than 2 weeks with no letter, or you have thrown it away, message us here and we will request a fresh code from HMRC for you.